Overhead conveyor

ABSTRACT

An overhead conveyor includes a monorail, a driving trolley having a drive wheel rolling along the monorail and a motor driving the drive wheel, a driven trolley disposed to be spaced apart from the driving trolley on the monorail and having a driven wheel rolling along the monorail, a hanger operatively suspended from the monorail, a first friction plate disposed on the hanger, a plurality of first jigs extending towards the first friction plate along the monorail, and a friction drive unit having a friction drive wheel disposed on the first jig so as to convey the first friction plate in a running direction and a drive motor driving the friction drive wheel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to KR patent application No. 10-2016-0041173, filed Apr. 4, 2016, which is incorporated herein by reference thereto.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to an overhead conveyor and, more particularly, to an overhead conveyor in which a hanger for carrying an object runs along a monorail in two running modes.

Description of the Related Art

Generally, an overhead conveyor is a mechanical apparatus that can move an object carried on a hanger using a conveyor.

U.S. Pat. No. 5,398,617 proposes an overhead conveyor capable of running a carriage along a rail using a drive wheel driven by an electric motor.

As well known to a skilled person in the art, in a conventional overhead conveyor, if an electric motor for driving a drive wheel, a carriage running along a rail, or the like breaks, a series of working processes to be performed along an assembly line has to be stopped.

If failed parts are not stably supplied, an operation rate of an assembly line is considerably reduced and productivity of a product such as automobiles may be decrease. Further, replacement of an aging overhead conveyor with a new one is costly and takes much time.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and the present invention is intended to propose an overhead conveyor and, more particularly, to an overhead conveyor in which a hanger for carrying an object runs along a monorail in two running modes.

In order to achieve the above object, according to one aspect of the present invention, there is provided an overhead conveyor including: a monorail disposed on an upper side of a working space; a driving trolley having a drive wheel rolling along the monorail and a motor driving the drive wheel; a driven trolley disposed to be spaced apart from the driving trolley on the monorail and having a driven wheel rolling along the monorail; a hanger operatively suspended from the monorail through a first frame of the driving trolley and a second frame of the driven trolley so as to carry an object thereon; a first friction plate disposed on one side of a flat upper end of the hanger; a plurality of first jigs extending from the upper side of the working space towards the first friction plate along the monorail; and a friction drive unit having a friction drive wheel disposed on a lower end of the first jig so as to convey the first friction plate in a running direction and a drive motor driving the friction drive wheel.

Particularly, according to the present invention, the hanger can be run along the monorail through driving of the driving trolley and/or friction drive unit.

Further, the overhead conveyor may include: a second friction plate disposed one the other side of the flat upper end of the hanger in such a manner as to be arranged parallel with the first friction plate relative to the monorail; a plurality of second jigs extending from the upper side of the working space towards the second friction plate along the monorail; and a support wheel disposed on a lower end of the second jig so as to convey the second friction plate in a running direction.

The driving trolley may further include a toggle clamp.

The friction drive unit may include a displacement means displacing the friction drive wheel.

The support wheel may include a displacement means displacing the support wheel.

The friction plate may have a plane part and downwardly-inclined surfaces on opposite ends of the plane part.

The plane part of the friction plate may extend longer than a distance between two adjacent friction drive wheels or support wheels.

Features and advantages of the present invention will be apparent from the following detailed description in conjunction with the accompanying drawings.

The terminologies or words used in the description and the claims of the present invention should not be interpreted as being limited merely to their common and dictionary meanings. On the contrary, they should be interpreted based on the meanings and concepts of the invention in keeping with the scope of the invention based on the principle that the inventor(s) can appropriately define the terms in order to describe the invention in the best way.

According to the present invention, in the overhead conveyor, the hanger for carrying an object can run along a monorail in two driving modes.

That is, according to the present invention, the hanger can run using an electric monorail system (EMS) and/or a friction drive system (FDS).

The present invention provides an advantage of implementing a running mode through a friction drive system based on the existing electric monorail system only with simple configuration.

That is, according to the present invention, upon the breakage of the driving trolley, the hanger can be run along the monorail by the friction drive unit, and upon the breakage of the friction drive unit, the hanger can be run along the monorail by the driving trolley, thereby facilitating a continuous, stable assembly process without interruption of an assembly line.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of an overhead conveyor according to a preferred embodiment of the present invention;

FIG. 2 is a front view of the overhead conveyor; and

FIG. 3 is a side view of the overhead conveyor.

DETAILED DESCRIPTION OF THE INVENTION

Hereinbelow, an overhead conveyor according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Advantages and features of the present invention and a method of accomplishing them will be apparent from the following embodiments in conjunction with the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. In the following description, it is to be noted that when the functions of conventional elements and the detailed description of elements related with the present invention may make the gist of the present invention unclear, a detailed description of those elements will be omitted.

The present invention relates to a suspended-type overhead conveyor 1 that can run a hanger 400 carrying an object thereon along a monorail 100 hanging from the ceiling on an upper side of a working space in two running modes. The overhead conveyor 1 includes a monorail 100 hanging from a ceiling, two trolleys 210 and 220 running along the monorail 100, and a hanger 400 coupled to the two trolleys 210 and 220 to carry an object thereon. The two trolleys 210 and 220 may be spaced apart from and connected to each other by means of a cross-piece, or otherwise may be disposed on an upper side of the hanger 400 in a spaced manner.

The monorail 100 is hung from and fixed to a support or the ceiling by means of a plurality of rail-support brackets 110, and may be an I-type rail having upper and lower horizontal flanges.

As illustrated, the driving trolley 210 and the driven trolley 220 are disposed to be spaced apart on the monorail 100.

The driving trolley 210 includes a drive wheel 211 rolling on an upper flange of the monorail 100, a motor 212 shaft-coupled to the drive wheel 211, and a toggle clamp 213. The motor 212 is shaft-coupled to the drive wheel so as to enable the drive wheel to be rotated. The toggle clamp 213 is an element that can transmit and/or interrupt a drive force of the motor 212 to the drive wheel 211. It is noted that the element is not limited to the toggle clamp, but may be replaced with other power transmission that is capable of transmitting or interrupting the drive force of the motor to the drive wheel.

If the toggle clamp 213 is released, the drive force of the motor 212 is not transmitted to the drive wheel 211. This means that the drive wheel 211 may be driven by other external force source, rather than the motor.

The driven trolley 220 is disposed on the monorail 100 in such a manner as to be spaced at a certain distance apart from the driving trolley 210 by a cross-piece. The driven trolley has a driven wheel 221 rolling on the upper flange of the monorail 100.

Here, the drive wheel 211 and the driven wheel 221 may be formed from rubber or urethane synthetic resin in order to prevent noise occurring due to friction with the monorail.

The driving trolley 210 is fixed to one end of the cross-piece or the hanger through a first frame 214 extending downwards from the monorail 100, and the driven trolley 220 is fixed to the other end of the cross-piece or the hanger through a second frame 224 extending downwards from the monorail 100. That is, in the overhead conveyor, the hanger 400 carrying an object thereon is suspended from and runs along the monorail 100.

The hanger 400 has arms 410 rotatably attached to opposite ends of a flat upper end thereof for loading an object such as a vehicle body.

The overhead conveyor can load and carry an object only with the operation of the driving trolley. When the driving trolley 210 runs along the monorail 100 along with the operation of the motor 212 after the vehicle body is loaded by arms 410 of the hanger 400, the driven trolley 220 also runs along the monorail 100 based on the motion of the driving trolley 210 while maintaining a constant distance from the driving trolley. Thus, the hanger 400 runs along the monorail 100 in an arrow direction in the above-mentioned driving manner. This driving manner is implemented based on an electric monorail system.

If one part of the driving trolley 210, such as the motor 212, is broken, the overhead conveyor cannot perform a series of subsequent processes on the vehicle body loaded on the hanger 400 moving along the monorail. In addition, for the limitation of the working space, a replaceable sub-rail cannot be installed. Thus, the overhead conveyor can be operated only after the motor is replaced or repaired.

Thus, the present invention proposes a solution to reduce dependence upon the driving trolley 210 driving the overhead conveyor 1 mounted on the monorail 100.

To this end, the present invention provides two friction plates 500 and 500′ on opposite sides of a flat upper end of the hanger 400. As illustrated, two friction plates 500 and 500′ are arranged parallel with the monorail 100.

The friction plates 500 and 500′ each have a plane part 511 fixed to the flat upper end of the hanger 400 and downwardly-inclined surfaces 512 on opposite ends of the plane part 511. The plane part 511 should be equal to or longer than an object-storage pitch of the hanger.

The overhead conveyor includes a friction drive unit 600, which has a friction drive wheel 610 in contact with an upper surface of the first friction plate 500 disposed on one side so as to forcedly carry the first friction plate 500 in a running direction, a drive motor 620 driving and rotating the friction drive wheel 610, and a displacement means (not shown) displacing the friction drive wheel 610. The friction drive unit 600 is disposed on a lower end of a first jig 121. The displacement means detects contact between the friction drive wheel 610 and the first friction plate 500 and displaces the height of the friction drive wheel 610 based on the detected result. The displacement means may be an elastic spring, a piezo-actuator, or the like.

In contrast, the overhead conveyor includes a support wheel 710 in contact with an upper surface of the second friction plate 500′ disposed on the other side so as to guide the second friction plate 500′ in the running direction. The support wheel 710 is rotatably disposed on a lower end of a second jig. The support wheel 710 serves to enable the hanger 400 to maintain a parallel position without tilting to one side during rotation of the friction drive wheel 610. Alternatively, the support wheel 710 may separately include a displacement means which can displace the height of the support wheel 710 according to contact between the support wheel 710 and the second friction plate 500′. The displacement means may be an elastic spring, a piezo-actuator, or the like.

When the first friction plate 500 is driven in the running direction with the rotation of the friction drive wheel 610, if the friction drive wheel 610 and/or the support wheel 710 does not come into contact with and slips along the upper surface of the friction plate 500 and/or 500′, the friction plates 500 and/or 500′ cannot be reliably carried. Thus, the friction drive wheel 610 and/or the support wheel 710 preferably includes the displacement means to allow the friction drive wheel and/or the support wheel to come into contact with the upper surface of the plane part of the friction plate 500 and/or 500′, ensuring reliable carrying of the friction plate 500 and/or 500′ with the rotation of the friction drive wheel 610 and/or the support wheel 710. The friction plates 500 and 500′ may have inclined surfaces 512 to dampen an impact between opposite ends of the friction plates 500 and 500′ and the friction drive wheel 610 and the support wheel 710 when the friction plates are carried towards the wheels.

The friction drive wheel 610 and the support wheel 710 may be formed from rubber or urethane synthetic resin to prevent noise occurring due to friction with the friction plates.

As illustrated, the friction drive unit 600 is hung from and fixed to a support or the ceiling by means of a plurality of first jigs 121, which are disposed along the monorail 100 so as to be spaced at a certain distance apart from the monorail. Preferably, the lower end of the first jig 121 is disposed on the first friction plate 500.

The support wheel 710 is hung from and fixed to a support or the ceiling by means of a plurality of second jigs 122, which are disposed along the monorail 100 so as to be spaced at a certain distance apart from the monorail. The lower end of the second jig 122 should be disposed on the second friction plate 500′.

In order to run the friction plates 500 and 500′ along the monorail 100 extending on an upper side of a working space, a plurality of friction drive wheels 610 should be arranged at regular intervals shorter than the whole length of the plane part of the first friction plate 500 Similarly, a plurality of support wheels 710 may preferably be arranged at regular intervals shorter than the whole length of the plane part of the second friction plate 500′. If the length of the plane part of the friction plate 500 is shorter than an interval between the friction drive wheels 610, neither of the two adjacent friction drive wheels 610 comes into contact with the friction plate 500, so that the friction plate 500 cannot be driven in the running direction.

As described before, the present invention is designed to reduce the dependence upon the hanger-driving manner based on EMS. For example, if the motor 212 of the driving trolley 210 is broken, an operator releases an operation of the toggle clamp 213 of the driving trolley 210 so as to ensure free rotation of the drive wheel 211 without the operation of the motor. Then, the operator can move the hanger 400 in an arrow direction by enabling the friction plate 500 to be driven in the running direction with the operation of the friction drive wheel 610 shaft-coupled to the drive motor 620.

That is, the present invention can move the hanger 400 operatively suspended from the monorail 100 with the operation of the driving trolley 210 or the friction drive unit 600.

The overhead conveyor according to the present invention can adopt EMS in which a controller is provided on the hanger so as to automatically operate the hanger or a power supply line and a signal line are provided on the monorail. The EMS and FDS can be operated on the ground.

Although the present invention has been described in detail with reference to exemplary embodiments for the purpose of illustrative explanation, the present invention is not limited to the above-mentioned embodiments, and it is apparent to those skilled in the art that modifications and improvements can be made to the embodiments within the technical spirit of the invention.

Such modifications and improvements belong to the scope of the invention, and a detailed scope of the invention will be defined by the accompanying claims 

What is claimed is:
 1. An overhead conveyor comprising: a monorail (100) disposed on an upper side of a working space; a driving trolley (210) having a drive wheel (211) rolling along the monorail (100), and a motor (212) driving the drive wheel (211); a driven trolley (220) disposed to be spaced apart from the driving trolley (210) on the monorail (100) and having a driven wheel (221) rolling along the monorail (100); a hanger (400) operatively suspended from the monorail (100) through a first frame (214) of the driving trolley (210) and a second frame (224) of the driven trolley (220) so as to carry an object thereon; a first friction plate (500) disposed on one side of a flat upper end of the hanger (400); a plurality of first jigs (121) extending from the upper side of the working space towards the first friction plate (500) along the monorail (100); and a friction drive unit (600) having a friction drive wheel (610) disposed on a lower end of the first jig so as to convey the first friction plate (500) in a running direction and a drive motor (620) driving the friction drive wheel (610), wherein the hanger (400) is able to be run along the monorail (100) through driving of the driving trolley (210) and/or friction drive unit (600).
 2. The overhead conveyor according to claim 1, wherein the overhead conveyor includes: a second friction plate (500′) disposed on the other side of the flat upper end of the hanger in such a manner as to be arranged parallel with the first friction plate (500) relative to the monorail (100); a plurality of second jigs (122) extending from the upper side of the working space towards the second friction plate (500′) along the monorail (100); and a support wheel (710) disposed on a lower end of the second jig so as to convey the second friction plate (500′) in a running direction.
 3. The overhead conveyor according to claim 1, wherein the driving trolley (210) includes a toggle clamp (213).
 4. The overhead conveyor according to claim 1, wherein the friction drive unit (600) includes a displacement means displacing the friction drive wheel (610).
 5. The overhead conveyor according to claim 2, wherein the support wheel (710) includes a displacement means displacing the support wheel.
 6. The overhead conveyor according to claim 2, wherein the friction plate (500, 500′) has a plane part (511) and downwardly-inclined surfaces (512) on opposite ends of the plane part.
 7. The overhead conveyor according to claim 6, wherein the plane part of the friction plate (500, 500′) extends longer than a distance between two adjacent friction drive wheels (610) or support wheels (710). 